Storyboard and Segue

On interface builder, it almost looks like 2 nibs same time with transition in middle (known as segue) .
You specify in code what you want to make happen. On the right side of scene you can see transition details : identifier: ShowAlternate, type is Modal, FlipHorizontal. There is an action on button inform Destination Controller that delegate will be self

src3.pdf on page 32:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
 {
if ([[segue identifier] isEqualToString:@"showAlternate"]) {
[[segue destinationViewController] setDelegate:self];
}
}

storyboard-and-unwind-segue

with storyboard you can have multiple views on a same board. It introduces segues. Segues represent transitions between screens. Opening a storyboard and your have pretty good idea of the UI flow at a glance.

• http://chrisrisner.com/Unwinding-with-iOS-and-Storyboards
• http://www.intertech.com/Blog/ios-unwind-segues/
• http://www.absoluteripple.com/1/post/2013/08/using-ios-storyboard-segues.html
• http://iwsaustin.com/blog/unwind-ios-storyboard-programmatically-guide/